Tautvilas or Towtwil (c.1352–1355 – September 1390) was one of the sons of Kęstutis, Grand Duke of Lithuania, and a strong supporter of his brother Vytautas the Great in his struggles against their cousin Jogaila.
Kęstutis and his son Vytautas was captured and held prisoners in Kreva castle.
In 1382 Kęstutis died under suspicious circumstances, while Vytautas managed to escape and sought allies among the Teutonic Knights.
Around the same time Jogaila banished Tautvilas from Navahrudak that he and his brother Vaidotas were ruling.
When Jogaila signed the Union of Krewo and became the King of Poland, he left his unpopular brother Skirgaila as a regent in Lithuania.